## CHAPTER 7: FRACTIONS AND DECIMALS

**Lesson 11: Using Mental Math**

**Goal**

Add and subtract decimals using mental math strategies.

**Instructions for Use**

**Decimal Darts** allows students to predict differences using estimation strategies.

To use Decimal Darts, click on the instructions button on the first screen. Read the instructions and click on “return”. Click on “Start Game” and then select the number of players on the next screen. Enter the names of the player(s) and click on the level of difficulty you would like to play. Click on the “continue” button to start playing. An invisible number line is superimposed on a dart board and you need to calculate the location of a balloon and then throw a dart to pop the balloon.

**Math at the Mall** allows students to solve money problems involving addition and subtraction.

To use Math at the Mall, click on the “How to” button on the first screen. Read the instructions and click on the “close” button at the top of the screen. Click on the “Start” button to start playing the game. Use the arrow keys on your keyboard to navigate through the mall. Use your math skills with adding and subtracting fractions to purchase items at the mall and collect four gold coins to complete the game.

**Laser Beams** allows students to use mental math strategies to solve problems.

To use Laser Beams, select a level (either Beginner, Intermediate or Advanced) but clicking on the level. Each level has seven questions. Read the number or question on the screen and use your rounding strategies to answer the question. Type in the answer and press enter before the asteroid gets away from you. A correct answer blasts the asteroid. An incorrect answer misses. Try to hit all seven asteroids in every round.